“The reason to work as an artist is to ask questions,” said Robert Wilson in 2008, at a lecture at Stanford University. “The reason to work is to say ‘What is it?’—and not to say what it is.” One of America’s most prominent figures in the world of experimental theater, Wilson is as enigmatic as his work is avant-garde. His innovative style has led him to collaborations with Lou Reed, Allen Ginsburg, and Mikhail Baryshnikov. In recent years, he’s reimagined classic operas such as Madama Butterfly and La Traviata. In this virtual performance, however, Wilson returns to the work of an equally radical artist, John Cage. To mark the 18th anniversary of the composer’s death, Wilson performs Cage’s famous “Lecture on Nothing.” —C.J.F.